Guayule

guayule [wī′yü·lē]

(botany)

Parthenium argentatum.A subshrub of the family Compositae that is native to Mexico and the southwestern United States; it has been cultivated as a source of rubber.

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Guayule 

(Parthenium argentatum), a rubber-bearing plant of the family Compositae. It grows in the deserts of the northern part of the Mexican plateau, as high as 2,000 m above sea level, and in Texas. It is an evergreen, heavily branched semishrub, reaching a height of 1 m, with a long branched tap root and numerous surface side roots. The leaves measure about 5-8 cm long, with pointed or lobed edges that may be notched or feathered, and contain 3-5 paired lobes. The long cauliform peduncles carry 7-30 small heads of flowers. The leaves, stems, and annual branches are covered with short, thick, silvery hairs. Rubber is found in the roots and the branches. Guayule also contains resin and ester oils.